A figure of merit (FOM) is a quantity typically used to characterize the performance of a device relative to other devices of the same type. In engineering, FOMs are often defined for a particular system, including materials, devices, or processes, in order to determine their relative utility for an application. In commerce, FOMs are often used as a marketing tool to convince consumers to choose a particular brand. FOMs are typically calculated based on one or more output characteristics of the system being evaluated. For example, in the specific case of a wireless power amplifier in a wireless electronic device, droop, the intentional loss in output voltage from the device as it drives a load, is commonly used as an FOM and is calculated from the output characteristics of the wireless device.
Time-varying output characteristics are obtained by performing multiple measurements of the system in question at various times. Typically, such measurements include at least a minimum amount of signal noise from various sources, resulting in variations in the output characteristic obtained. For example, in the case of electrical measurements for an electronic device, an output characteristic may exhibit shot noise, thermal noise, flicker (1/f) noise, burst noise, avalanche noise, and/or noise induced by environmental factors. Accordingly, such variations in the output characteristics of the electronic device can result in inaccurate FOM values. In some cases, the amount of measurement noise can mask the behavior of the output characteristic entirely, resulting in measurements and associated FOMs being of little or no utility. As a result, there have been considerable efforts made to reduce and/our counter the effects of different noise sources in test equipment. For example, some types of high accuracy electronic test equipment include additional hardware features specifically configured to counter particular noise sources to minimize the introduction of noise into the output characteristic used for calculating the FOM. In some cases, the electronic test equipment includes a regression analysis system for generating a model for the data points. Such regression analysis systems are typically configured to generate a mathematical function that models the output response.